In the renewed scandal regarding Thomas Jefferson’s and his concubine, Sally Hemings, we must not forget two things: (1) Jefferson did NOT sire “black” children and (2) their mother was NOT a “black” woman. Nothing about the Sally Hemings/Thomas Jefferson story makes sense unless the whiteness of the Hemings family is emphasized.
“Negro blood” by itself did not make anyone a slave. It was the maternal descent rule of partus sequitur ventrem that enslaved a person – if the maternal slave line was unbroken by legal manumission. A slaveholder could, legally, have more “negro blood” than his slave. A legal white man could have more Negro blood than a so-called light mulatto who would be legally white if he were manumitted. The latter was possible because the general Southern rule was to establish one-eighth or less “Negro blood” as the dividing line between “white” and “mulatto.” Even this could be modified by such things as reputation, acceptance by the local white community, property ownership, etc. Hard as it may be for persons raised on “one drop” mythology to believe, a person classified as a “mulatto slave” would, if manumitted and one-eighth or less black, legally become a free white person rather than a “free colored.” As Thomas Jefferson, himself stated:
Our canon considers two crosses with the pure white, and a third with any degree of mixture, however small, as clearing the issue of the Negro blood. But observe, that this does not reestablish freedom, which depends on the condition of the mother, the principle of the civil law, partus sequitur ventrem being adopted here.
It is ridiculous to say, for example, that Eston Hemings Jefferson “pretended” to be white or “passed” for white. He didn’t “pass” for anything. He WAS legally white. We should also note that all of Eston’s descendants are white – if such a thing as “whiteness” or “blackness” can be said to exist at all. Remember that “whites” are part of the “multiracial” continuum (in contrast to the popular “one drop” myth that all “blacks” are racially “mixed” and “whites” are all “pure).
An excellent resource regarding the political importance of “white slavery” is The Forgotten Cause of the Civil War: A New Look at the Slavery Issue by Lawrence R. Tenzer.